1. Field of the Invention
The present invention relates to a light emitting diode package, more particularly, which is superior in heat radiation properties and easily manufacturable.
2. Description of the Related Art
In general, a light emitting diode (LED) is spotlighted in various fields as an environment-friendly light source which does not trigger pollution. Recently, the LED has found its application broadened to various fields such as indoor and outdoor lightening, car headlights, backlight units (BLU) of display devices. Thus, the LED is required to possess high efficiency and superior heat radiation properties. The high efficiency LED can be obtained primarily by improving materials and structure thereof. Besides, structure and materials of an LED package need to be elevated in quality.
Such an LED generates high-temperature heat. Thus, the LED package should effectively radiate the high-temperature heat generated from the LED. Otherwise, the LED is increased in temperature and thus degraded in properties thereof. This accordingly shortens useful life of the LED. Therefore, there have been ongoing efforts to effectively radiate heat generated from the LED. To enhance radiation properties of the LED package, PCT No. WO2002/089219 discloses a technology for utilizing, as an LED package substrate, a metal substrate which has an electrode pin penetrating a through hole and surrounded by an insulator to be separated from the through hole. Also, Japanese Laid Open Patent Application No. 2005-210057 teaches a technology for integrating an insulating resin with a plurality of separate metal members to utilize as an LED package substrate.
FIG. 1 is a schematic cross-sectional view illustrating a conventional light emitting diode package. Referring to FIG. 1, the conventional light emitting diode package 10 includes a plurality of metal members 1b, a resin 1a formed between the metal members 1b, and a resin 1c for fixing the metal members 1b, which are all integrated together into a substrate 1. An LED device 5 is mounted on the substrate 1. The LED device 5 is electrically connected to the metal members 1b through conductive bonding materials 6 and 7. Reflective members 2 each having a reflecting surface 2b are formed on the substrate 1. The light emitting diode package 10 has a transparent member 3 formed thereon to emit light from the LED device 5 upward. Alternatively, the light emitting diode package 10 may contain phosphors therein to convert a wavelength of light from the light emitting diode 5.
The LED device 5 radiates light and heat at the same time. Here, the heat is radiated outside through the metal members 1b of the substrate 1. To radiate heat, the metal members 1b should be thermally conductive and properly sized. However, the metal members 1b of the substrate 1 are fixed through resins 1a and 1c, and thus heat is radiated through a smaller area which excludes portions of the resins 1a and 1c. Furthermore, the metal members 1b are integrated into the substrate 1 through resins 1a and 1c and the reflective members 2 should be formed on the substrate 1. This renders the light emitting diode package difficult to manufacture.